An analysis has good news for patients with rheumatoid arthritis, or RA, who are concerned about the potential side effects of biologic disease-modifying antirheumatic drugs. A meta-analysis of 63 randomized controlled trials found that biologics taken on their own, or in combination with methotrexate, pose little increased risk of cancer, at least in the short term.

The largest meta-analysis to date on the much-debated subject, it adds to a growing body of evidence that biologics do not appear to significantly increase cancer risk. The findings were published in 2012 in the Journal of the American Medical Association (JAMA).

“This is a reassuring message,” says senior author Maria E. Suarez-Almazor, MD, PhD, a professor in the department of general internal medicine at The University of Texas MD Anderson Cancer Center, in Houston.

Dr. Suarez-Almazor acknowledges that many RA patients worry about side effects from taking biologics because the drugs suppress the immune system, which normally protects a person from disease and infection. The perceived threat of increased cancer risk is particularly alarming because RA patients in general have a slightly elevated risk of certain cancers – including lymphoma and lung cancer – although it’s not clear why.

Dr. Suarez-Almazor reviewed data from 63 clinical trials involving almost 30,000 patients who were followed for up to three years. Depending on the individual studies, control groups received either placebo or traditional disease-modifying antirheumatic drugs (such as methotrexate); other participants took any of the nine FDA-approved biologic medications – with or without methotrexate – for RA for at least six months. These include TNF-alpha inhibitors etanercept, or Enbrel; adalimumab, or Humira; certolizumab pegol, or Cimzia; golimumab, or Simponi; and infliximab, or Remicade. The other types of biologics studied were rituximab, or Rituxan; abatacept, or Orencia; tocilizumab, or Actemra; and anakinra, or Kineret.

The findings are promising. “What we found overall is that for biologics, in general, there appears to be very little risk or no risk at all with respect to cancer for about a year or so,” Dr. Suarez-Almazor explains.

Among the 3,615 patients taking only a biologic, researchers found a cancer risk of 0.64 percent. Among the 15,989 patients taking a biologic in combination with methotrexate, there was a cancer risk of 0.77 percent. And among the 9,819 patients in control groups, there was a cancer risk of 0.66 percent.

“The differences in these numbers are really very small and insignificant, not unlike small differences that happen just by chance,” Dr. Suarez-Almazor says.